Sending the value people input in DataTable in C# to microcontroller

Question

I'm trying to send the value which people input from DataTable to microcontroller, but when I check again by TeraTerm the value in microcontr., the result I get is wrong.

The image :

Here my code for grid init:

private void Form1_Load(object sender, EventArgs e)
{
    //Data table
    DataTable table = new DataTable();

    //Column
    table.Columns.Add("TPS");
    table.Columns.Add("500", typeof(float));
    table.Columns.Add("750", typeof(float));
    //Row
    table.Rows.Add("100%");
    table.Rows.Add("95%");
    table.Rows.Add("90%");

    //Data Grid View
    dtGridView.DataSource = table;

    //Set width
    dtGridView.Columns[0].Width = 40;
    dtGridView.Columns[1].Width = 40;
    dtGridView.Columns[2].Width = 40;

}

And the sending:

private void btnSend_Click(object sender, EventArgs e)
{
    try
    {
        for (int i = 0; i < dtGridView.Rows.Count; i++)
            for (int j = 0; j < dtGridView.Columns.Count; j++)
            {
                object o = dtGridView.Rows[i].Cells[j].Value;

                if (P.IsOpen == true)
                {
                    P.WriteLine(o.ToString());
                    MessageBox.Show("Write succesfully!");
                    P.Close();
                }
            }
    }
    catch(Exception ex)
    {
        MessageBox.Show("Unable to write to COM port");
    }
}

Answer 1

When you run this loops:

for (int i = 0; i < dtGridView.Rows.Count; i++)
    for (int j = 0; j < dtGridView.Columns.Count; j++)
    {
        object o = dtGridView.Rows[i].Cells[j].Value;
        if (P.IsOpen == true)
        {
            P.WriteLine(o.ToString());
            MessageBox.Show("Write succesfully!");
            P.Close(); // <<<<<<<<<<<<<<<<<<< this close the connection immediately after 1st val.
        }
    }

Instead try to close it after the loop.

for (int i = 0; i < dtGridView.Rows.Count; i++)
    for (int j = 0; j < dtGridView.Columns.Count; j++)
    {
        object o = dtGridView.Rows[i].Cells[j].Value;
        if (P.IsOpen == true)
        {
            P.WriteLine(o.ToString());
            MessageBox.Show("Write succesfully!");
        }
    }

if (P.IsOpen == true)
   P.Close();             // like this

Answer 2

The issue if you're calling P.Close() after the first iteration as others have noted. Generally with serial communications after connect I would just keep the connection open until the user explicitly disconnected. I would recommend removing P.Close(); from the loop and instead adding a disconnect button that calls P.Close();.

This should simplify your code as well as the send button will only be concerned with writing data and not also managing the state of the serial communications.

Answer 3

Tks everyone ,i sent value successfully . But if i do as the way i did , it will send each value of the table . Now i want to click the button send , all the values i input will send in one time . Is the anyway to do it ?

Here the image attached : enter image description here